1. Field of the Invention
The present disclosure is directed to devices and methods for catheterization of the urinary bladder. More particularly, the present invention relates to such devices and methods employing a sheathed catheter.
2. Background of the Invention
The occasional or periodic catheterization of an individual's urinary bladder is a common practice today for many persons who are in a hospital setting, a nursing home, doctor's office, rehabilitation facility or at home. For instance, a patient may be catheterized to treat such conditions as urinary retention, the inability to evacuate urine, or for the purpose of obtaining a sterile urine specimen from a patient in a doctor's office.
Generally, catheterizations may be assisted (non self-catheterizations) or unassisted (self-catheterizations). In assisted catheterizations, a nurse may perform the catheterization by employing a catheterization tray (“cath tray”), which typically includes a sterile drape, gloves, a conventional catheter, antiseptic solution, cotton balls, lubricant, forceps, underpad and a urine collection container. All of these items are typically packaged together and sterilized. However, to perform the catheterization, the nurse must open the tray and handle the various items in the tray. Although special precautions may be taken, maintaining a sterile environment during the procedure may present challenges. Further, because multiple steps are involved in the procedure, a nurse may spend a significant amount of time (e.g., 10-15 minutes) carrying out each catheterization. In addition, conventional “cath tray” procedures may be expensive or otherwise impractical for use with some individuals and situations today.
For some of the above-stated reasons, many individuals, if capable, would prefer to perform self-catheterization. For many, the level of risk and discomfort of repeated catheterizations carried out over the course of a day (e.g., at 3-6 hour intervals) are offset by the accompanying convenience, privacy or self-reliance that is achieved. Some of the major difficulties that arise in self-catheterization are problems relating to maintaining the required level of sanitation during the procedure, and the difficulty of sometimes performing the procedure under conditions of restricted space and privacy.
A variety of catheterization kits and products are currently available. For instance, U.S. Pat. No. 6,090,075 (House I) discloses a catheter assembly with a catheter introducer member for positioning catheter assembly against the urethral opening, a flexible catheter, and a flexible thin-walled sheath surrounding the catheter and partially covering the catheter introducer.
Some catheterization assemblies and kits employ hydrophilic catheters that are self-lubricating when wetted with a fluid (e.g., water) prior to use. U.S. Pat. No. 6,409,717 (Astra Aktiebolag) and U.S. Pat. No. 6,736,805 (AstraZeneca AB) describe apparatus for wetting a hydrophilic urinary catheter, having a wetting receptacle which defines a wetting fluid receiving area for receiving the catheter and a wetting fluid container having a discharge outlet movable from a closed position to an open position on application of a predetermined condition thereto to enable the wetting fluid to be discharged from the container. U.S. Pat. No. 6,634,498 (Coloplast A/S) describes certain urinary catheter assemblies including a urinary catheter having at least a part of its surface a hydrophilic surface layer intended to produce a low-friction surface character of the catheter by treatment with a liquid swelling medium during manufacture of the catheter assembly, and a catheter package having a cavity for accommodation of the catheter. The package includes a compartment having walls of a gas impermeable material that accommodates the liquid swelling medium and a pre-treated catheter for long term preservation of the low-friction surface character and provision of a ready-to-use catheter assembly.
Some catheter assemblies include a protective sheath that surrounds the catheter or a portion thereof. The sheath may serve multiple purposes. For instance, the sheath may prevent contamination of the catheter as the catheter is handled prior to and/or during use. In addition, in some hydrophilic catheters, the sheath may contain a wetting agent used to lubricate the catheter during use. Failure of the sheath may lead to various problems, such as urinary tract infections, pain, and/or difficult catheterizations.
In some instances, a flexible catheter sheath is gathered near the distal end of the catheter (e.g., end relatively away from the patient) during use to allow the catheter to advance beyond the sheath and into the patient's urethra. As the sheath is gathered, the volume within the sheath may decrease. In assemblies in which the sheath lumen is not in fluid communication with a collection receptacle or the environment outside the sheath, some fluid contained within the sheath (e.g., air, wetting agent, etc.) may become trapped and compressed, resulting in a pressure buildup within the sheath (e.g., the sheath may “balloon-up”). A slight to moderate pressure build-up within the sheath may not result in any problems; however, excessive pressure build-up within the sheath may lead to noticeable problems. For example, excessive pressure buildup within the sheath may result in forces opposing further gathering of the sheath, thereby limiting the degree to which the catheter may be advanced into the urethra. In addition, as a consequence of an excessive pressure build-up, the sheath may “balloon-up,” potentially limiting the ability of the user to adequately grasp the catheter through the sheath. This consequence may detrimentally affect the ability of the user to control and manipulate the catheter during insertion. Further, an extreme pressure build-up may cause the sheath to rupture, potentially compromising the ability of the sheath to prevent contamination of the catheter contained within. In addition, a tear or rupture in the sheath may detrimentally impact the ability of the sheath to contain a wetting agent (e.g., hydrophilic catheters), create a clean-up nuisance, and possibly result in an unexpected, abrupt movement of the catheter. In instances in which excessive pressure-build-up within the sheath could arise, it would be advantageous to have a means to relieve some of the pressure build-up within the sheath lumen.
Accordingly, there remains a need for an easy-to-use, sanitary and disposable catheterization assembly. Such an assembly would be well received it if includes a flexible sheath capable of protecting the catheter from contamination, is capable of containing a lubricant or a wetting agent in the case of a hydrophilic catheter, is capable of being gathered to advance the catheter, and is capable of deterring excessive pressure build-up within the sheath lumen when the sheath is gathered.